HP Integrity rx7620 Server - User Service Guide, Sixth Edition

For example, it is difficult to see cable connection points on the hardware if lighting is inadequate.
Adequate lighting reduces the chances of connector damage when cables are installed or removed.
The minimum recommended illumination level is 70 foot-candles (756 lumens per square meter)
when the light level is measured at 30 inches (76.2 cm) above the floor.
Working Space for Server Access
The recommended working space for performing maintenance on the server is three feet. The
work space will permit at least a 90 degree opening of equipment doors or hinged panels. When
planning for the working space area, consider whether access to the server will be at the front,
the side, or the rear of the server.
Power Consumption
When determining power requirements, you must consider any peripheral equipment that will
be installed during initial installation or as a later update. To determine the power required to
support these devices, see the applicable documentation for such devices.
Electrical Load Requirements (Circuit Breaker Sizing)
NOTE: LAHJ and should make the final decision regarding adherence to country-specific
electrical codes and guidelines.
It is good practice to derate power distribution systems for the following reasons:
• To avoid nuisance tripping from load shifts or power transients, circuit protection devices
should never be run above 80% of their root-mean-square (RMS) current ratings.
• Safety agencies derate most power connectors to 80% of their RMS current ratings.
Power Quality
The server is designed to operate over a wide range of voltages and frequencies. The server has
been tested and shown to comply with EMC Specification EN50082. However, damage can occur
if these ranges are exceeded. Severe electrical disturbances can exceed the design specifications
of the equipment.
Sources of Voltage Fluctuations
Voltage fluctuations, sometimes called glitches, affect the quality of electrical power. Common
sources of these disturbances are:
• Fluctuations occurring within the facility’s distribution system
• Utility service low-voltage conditions (such as sags or brownouts)
• Wide and rapid variations in input voltage levels
• Wide and rapid variations in input power frequency
• Electrical storms
• Large inductive sources (such as motors and welders)
• Faults in the distribution system wiring (such as loose connections)
• Microwave, radar, radio, or cell phone transmissions
Power System Protection
The server can be protected from the sources of many of these electrical disturbances by using:
• A dedicated power distribution system
• Power conditioning equipment
• Over- and under-voltage detection and protection circuits
• Screening to cancel the effects of undesirable transmissions
• Lightning arresters on power cables to protect equipment from electrical storms
182 General Site Preparation Guidelines